Pilot lamp arrangement for multiplex telegraph printers



July 18, 1933.

L. W. FRANKLIN ET AL PILOT LAMP ARRANGEMENT FOR MULTIPLEX TELEGRAPH PRINTERS Filed Jan. 8, 1932 7`0 PEGI/LAWN@ RELAY vll'.

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UNITED stares PATENTOFFICE LAURENCE W. rnANKLin, or nnnnwannmnnnrnanx J. MAUS, or rATERsonNEw JERSEY, ASSIGNORS TO 'EE-IE 'VESTERNUNION TELEGRAPHUCOMPANY, 0F NEW YORK-av. Y., a ccaroRA'rioN or NEW YORK v y rrnofr iraniennes-rientranti: non MULTIPLEXY'TELEGRAPH PRINTERS Appiication sied January s, 1932. seriai'No. 585,580.

This invention relates to an arrangement y for the pilot lamps associated with the printing telegraph machines in multiplex systems.

The reliable operation of the printer depends upon the proper functioning of its various circuits, relays and magnets. ure of some relay to operate or a fault in a circuit might produce a condition whichA would make the printerinoperative, leaving it in a dead-locked or tied up condition. In such an event, the distant station might still continue to transmit, but the printer impulses.

vwould fail torecordthe signals. To guard against such loss of messages or to prevent' transmission to a tied up printer, means are provided for immediately indicating when such a condition exists.

The indicator heretofore employed consisted of a tungsten filament lamp, known as the pilot orftie up lamp mounted within each printer in plain view of the operator or attendant and so connected to the distribuinto forty segments. The alternate segments are divided into four channel groups7 of five segments each; The remaining five segments in each group are connected together and to one terminal of the pilot lamp, the other lampV terminal being connected to the printer battery. The receiving segments receive only the central portion or half of the` receiving The remaining portion of eac impulse is employed to light the pilot lamps.

In certain systems the terminal require-` ments necessitate the use ofthe segments heretofore employed to operate the pilot `or tie up lamps, to operate certain relays. Consequently the pilot lamp has been placed in the A failcommon return of the five printer selector magnets. -A lamp iilament 1n the common return is unsatisfactory both because a lamp of sufficiently low resistance will not respond to the signals and because the hazard of the w burning out of the filament.

The object of our inventiony isto` overcome the objections above mentioned by providing Van arrangement employing tubes of the gasflled type without ilaments,such as the neon y glow lamp, and wherein vthepilot or tie up llamp is inductively connected to the common to the accompanying drawing in which Fig. 1

is a diagrammatic illustration showing our invention applied to the `common return circuit of the 'printer magnets; and Fig. 2 illustrates the relation between the'fluX wave generated in the transformer core by the signal impulses andthe sharp peak voltages generated in the'secondary and impressed upon the pilot or tie up lamp. l

The line L is connected toithefsolidring of the multiplex distributor MX. The segmented receiving-ring isdivided into forty segments, ten foreach'channel. `Segments l to 5 of the"A channel are1 connected respectively to the five' selector magnets of the printer A, the alternate segments being connected to the regulating relay. i 7

In thecominon return circuit CR of the printer selecting magnets, we connect .the primary `coil P of a transformer T, the secondary coil S being connected to the terminals of a neon flow discharge lampN.` `As the voltage induced in the` secondary coil is proportional to the rater of change offlux with respect to time, an approximately rectangular flux wave as shown in Fig.` 2a wouldv i ducedvoltage wave, a magnetic circuit constructed as illustrated, vwith one part of much smaller cross-section than the remainder may be employed. However, this particular' construction is not essential.

The use of a glow lamp possesses manyadvantages over thel filament lamp heretofore `employed asa pilot or tie up lamp. It has to signal impulses which consists in producing an arc discharge in a gaseouspath in response to voltages impressed upon the machine loy the signal impulses.

2. In a telegraph system, a printer responsive to signal impulses a gaseous glow lamp in inductive relation to the printer circuits and operated hy voltages impressed upon said circuits by the signal impulses.

3. In a telegraph system, a printer having selective magnet-s responsive to signal impulses, a common return circuit for said magnets, a transformer having a primary coil in said return ci rcuiti an d a glow discharge lamp in circuit With the secondary coil of said transformer.

LAURENCE W. FRANKLIN. FRANK J. MAUS. 

